Our purpose is to compare the results of the corticotropin releasing hormone (CRH) stimulations test to the results of ACTH and/or insulin tolerance tests in patient with various forms of adrenal insufficiency. We will test the hypothesis that the CRH test is as discriminating a measure of adrenocortical reserve as is the ACTH test in ACTH insufficient individuals and that the CRH test is as specific a measure of pituitary ACTH reserve as is the ITT.